Results: :
The expression of CD103 was 66.2±2.8% and 29.1±5.4%in Tregs and non–Tregs, respectively. There was no significantdifference in the expression of CTLA4 and CD28. But interestingly,the expression of CD94 and Foxp3 were enhanced in OT–1Tregs.On the other hand the expression of CD25 and GITR were downregulated. In Tregs and non–Tregs respectively: CTLA40.28% vs. 0.81%; CD28 1.00% vs. 1.37%; CD94 8.04% vs. 1.30%;Foxp3 88.1% vs. 0.33%; CD25 2.24% vs. 21.2% and GITR 67.8% vs.91.9%.

Conclusions: :
The ACAID CD8+ Tregs can be identified by CD103,Foxp3 and CD94 expression. Thus, ACAID OT–1CD8+ Tregsexpress different cell surface and intracellular molecules fromnon–Tregs. The ACAID CD8+ Tregs also differ in its expressionof known regulatory molecule from published studies on CD4+CD25+ Tregs. The prediction is that the ACAID efferent Tregsuse novel regulatory pathways to suppress CD4+ effector cellsand these pathways differ from those used by afferent Tregs.